From: "Joe" <rigdonj(a)cfl.rr.com>
 I don't think you can scan them directly into a PDF format. AFIK PDF is
propriatary to Adobe and I
 think you have to have their software to convert your
image files to PDF. 
Their software also
There are some other vendors than Adobe's rather expensive Distiller.  I use
PDF Factory from FinePrint (
www.fineprint.com), and a search at 
download.com
shows a number of other tools.  I can highly recommend PDF Factory, it's
worked flawlessly for me, and the Pro version supports links and bookmarks.
Jim